As well known in the art, buildings exterior walls are clad with boards to provide an exterior surface ready for painting and the like.
The boards are generally fastened to the wall studs that comprise the frame of a building with an even overlap up the wall. The top portion of a lower board is covered by the bottom portion of the next highest board, with all the boards in a parallel configuration. The boards must be as parallel as possible to provide uniform covering of the frame and to maintain a neat appearance.
Generally, fasteners pierce the top portion of the board and the overlapping by the bottom portion of the next highest board provides a neat appearance by concealing the fasteners.
In this method of construction the lower most board is positioned horizontally, usually with the aid of a spirit level or such device, to establish a datum. The other boards are then positioned to overlap one another, at equal intervals up the frame parallel to this datum, until the frame is concealed.
This method of cladding would generally require at least two people to locate the boards in an even spacing parallel to one another. The boards being up to several meters in length are difficult to position, align and hold in position whilst fasteners are attached. This task becomes even more difficult and time consuming if only one person is attaching the boards to the building frame.
In an attempt to overcome these problems some boards are provided with an aligning spline located near the lower edge of, and parallel to, the board's longest side. These aligning splines require only one board (the lower most) to be positioned horizontally. The aligning splines of successive higher boards locate against the top edge of the board below and as such they are held at a uniform spacing and in a parallel relationship. In this situation only one person is required to insert the fastening means as the board rests under its own weight in the correct position.
However, boards of this type have the aligning spline factory installed and the height of the boards in relation to one another is fixed. Positioning boards at different heights, for example when approaching the top of the building frame, becomes very difficult. Also, when forming butt joints, on corners for example, the spline must be cut away to allow room for the joint, before the board can be positioned. A similar problem is encountered when attempting to use joint trimmers between two boards side by side. As the splines are rigidly attached to the boards they are difficult to trim.
Furthermore, the boards cannot be stacked easily due to the spline protruding from the board. Inventory levels are also required to be higher than normal since both splined and conventional boards may be required to be kept in stock.